microg/GmsCore · error · UnsupportedOperationException

Unsupported method call %s(%s).

Error message

Unsupported method call %s(%s).

What it means

AccountContentProvider.call() supports only a fixed set of methods (get_accounts, and clear-password when the caller has google package permission). Any other method name throws UnsupportedOperationException.

Source

Thrown at play-services-core/src/main/java/org/microg/gms/auth/AccountContentProvider.java:101

                                    (hasGooglePackagePermission || AuthPrefs.isAuthVisible(getContext()))) {
                                Log.d(TAG, "Make account " + account + " visible to " + packageName);
                                am.setAccountVisibility(account, packageName, VISIBILITY_VISIBLE);
                            }
                        }
                    }
                }
                if (accounts == null) {
                    accounts = new Account[0];
                }

                result.putParcelableArray(PROVIDER_EXTRA_ACCOUNTS, accounts);
                return result;
            } else if (PROVIDER_METHOD_CLEAR_PASSWORD.equals(method) && hasGooglePackagePermission) {
                Account a = extras.getParcelable(PROVIDER_EXTRA_CLEAR_PASSWORD);
                AccountManager.get(getContext()).clearPassword(a);
                return null;
            }
            throw new UnsupportedOperationException(String.format("Unsupported method call %s(%s).", method, arg));
        } finally {
            Binder.restoreCallingIdentity(identityToken);
        }
    }

    @Nullable
    @Override
    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
        throw new UnsupportedOperationException();
    }

    @Nullable
    @Override
    public String getType(Uri uri) {
        return "text/plain";
    }

    @Nullable

View on GitHub (pinned to 157c9d86ac)

Solutions

  1. Use the exact supported method string (the PROVIDER_METHOD_GET_ACCOUNTS constant value) in your call().
  2. For clear-password, ensure the caller has the google package permission, otherwise the call is rejected.
  3. Wrap the call in try-catch for UnsupportedOperationException and fall back to AccountManager APIs.
  4. Check the microg source for the current list of supported provider methods for your version.

Example fix

// before
resolver.call(uri, "getAccounts", arg, extras);
// after
resolver.call(uri, "get_accounts", arg, extras); // match PROVIDER_METHOD_GET_ACCOUNTS
Defensive patterns

Strategy: try-catch

Validate before calling

if (!"get_accounts".equals(method) && !("clear_password".equals(method) && hasGooglePermission)) throw new IllegalArgumentException("unsupported method: " + method);

Try / catch

try { resolver.call(uri, method, arg, extras); } catch (UnsupportedOperationException e) { // fall back to AccountManager }

Prevention

When it happens

Trigger: Calling ContentResolver.call() with a method string other than PROVIDER_METHOD_GET_ACCOUNTS, or calling PROVIDER_METHOD_CLEAR_PASSWORD without holding the google package permission (the branch falls through to the throw).

Common situations: Typos or version drift between caller method string and provider constant; calling clear_password from an unprivileged app so the permission-guarded branch is skipped; copy-pasted code from a newer/older play-services version using renamed methods.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

AI-assisted analysis of microg/GmsCore@157c9d86ac (2026-09-06). Data as JSON: /api/errors/28fc016d2588217e. Report an issue: GitHub.